Rotary fan press

ABSTRACT

A liquid extraction assembly for extracting liquid from a mass comprising a housing having an inlet and an outlet. The housing further includes a path between the inlet and the outlet. The housing is configured to have the mass forced into the inlet to move the mass from the inlet to the outlet. The housing includes two substantially parallel rotating screens rotating side by side and apart from one another, with the path extending between the screens. Each screen defines one wall of the path. Each rotating screen includes a plurality of non-circular openings located at the path. Pressure from mass forced into the input presses the mass against the non-circular openings of the rotating screens to thereby force at least a portion of liquid in the mass to pass through the non-circular openings of the rotating screens.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/113,490, filed on May 23, 2011, which is a continuation of U.S.patent application Ser. No. 12/581,509, filed on Oct. 19, 2009, entitledROTARY FAN PRESS, now U.S. Pat. No. 7,945,225, which is a continuationof U.S. patent application Ser. No. 11/573,402, filed on Feb. 8, 2007,entitled ROTARY FAN PRESS, now U.S. Pat. No. 7,895,943, which is aNational Stage of International Application No. PCT/US2005/028041, filedon Aug. 8, 2005, entitled ROTARY FAN PRESS, which claims priority toU.S. Provisional Patent Application No. 60/600,004 filed on Aug. 9,2004, entitled ROTARY FAN PRESS.

FIELD OF THE INVENTION

The present invention concerns a liquid extraction machine, and moreparticularly relates to liquid extraction machines having a rotary fanpress.

BACKGROUND OF THE INVENTION

Apparatus for feeding, compressing, liquid extraction, washing andchemical treatment of sludge, slurries or other wet materials are wellknown. Such equipment finds particular application in the pulp and paperindustry, waste water treatment, mineral processing, agriculture, foodprocessing, fisheries, breweries, wineries, chemical processing, oil andtar sands industry, etc.

An improved apparatus is desired for feeding, compressing, liquidextracting, washing and chemical treating of the sludge, slurries orother wet materials.

SUMMARY OF THE PRESENT INVENTION

An aspect of the present invention is to provide a liquid extractionassembly for extracting liquid from a mass comprising a housing havingan inlet and an outlet. The housing further includes a path between theinlet and the outlet. The housing is configured to have the mass forcedinto the inlet to move the mass from the inlet to the outlet. Thehousing includes two substantially parallel rotating screens rotatingside by side and apart from one another, with the path extending betweenthe screens. Each screen defines one wall of the path. Each rotatingscreen includes a plurality of non-circular openings located at thepath. Pressure from mass forced into the input presses the mass againstthe non-circular openings of the rotating screens to thereby force atleast a portion of liquid in the mass to pass through the non-circularopenings of the rotating screens.

These and other aspects, objects, and features of the present inventionwill be understood and appreciated by those skilled in the art uponstudying the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a top view of a system for extracting liquid from a mass ofthe present invention.

FIG. 2 is a front view of the system for extracting liquid from a massof the present invention.

FIG. 3 is a side view of the system for extracting liquid from a mass ofthe present invention.

FIG. 4 is a schematic of the system for extracting liquid from a mass ofthe present invention.

FIG. 5 is an exploded rear perspective view of a liquid extractionassembly and a motor assembly of the system of the present invention.

FIG. 6 is an exploded cross-sectional view of the liquid extractionassembly of the present invention.

FIG. 6A is a cross-sectional view of a pair of liquid extractionassemblies and a transfer housing of a motor assembly of the system ofthe present invention.

FIG. 7 is a cross-sectional view of a rotary screen assembly of theliquid extraction assembly of the present invention.

FIG. 8 is a rear view of an inner housing shell of the liquid extractionassembly and the motor assembly of the liquid extraction system of thepresent invention.

FIG. 9 is side view of the inner housing shell of the liquid extractionassembly and the motor assembly of the liquid extraction system of thepresent invention.

FIG. 10 is a first side view of the inner housing shell of the housingof the liquid extraction assembly of the present invention.

FIG. 11 is a second side view of the inner housing shell of the housingof the liquid extraction assembly of the present invention.

FIG. 12 is a side view of a center seal of the liquid extractionassembly of the present invention.

FIG. 13 is a front view of the center seal of the liquid extractionassembly of the present invention.

FIG. 14 is a first side view of a drive wheel of the rotary screenassembly of the liquid extraction assembly of the present invention.

FIG. 15 is a second side view of a slotted filter screen and the drivewheel of the rotary screen assembly of the liquid extraction assembly ofthe present invention.

FIG. 16 is a cross-sectional view of the slotted filter screen of thepresent invention.

FIG. 17 is a side view of the motor assembly, the inner housing shell,the slotted filter screen, the drive wheel, the drive shaft and thecenter seal of the liquid extraction assembly of the present invention.

FIG. 18 is a side view of the motor assembly, the inner housing shell,the rotary screen assembly, the drive shaft, and the center seal of theliquid extraction assembly of the present invention.

FIG. 19 is an end view of an exit of the liquid extraction assembly ofthe present invention in a first position.

FIG. 19A is an end view of the exit of the liquid extraction assembly ofthe present invention in a second position.

FIG. 19B is a side cross-sectional view of the exit of the liquidextraction assembly of the present invention.

FIG. 19C is a side cross-sectional view of the exit of the liquidextraction assembly of a second embodiment of the present invention.

FIG. 19D is an end view of the exit of the liquid extraction assembly ofa third embodiment of the present invention.

FIG. 19E is an end view of the exit of the liquid extraction assembly ofa fourth embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

For purposes of description herein, the terms “upper,” “lower,” “right,”“left,” “rear,” “front,” “vertical,” “horizontal,” and derivativesthereof shall relate to the invention as orientated in FIG. 1. However,it is to be understood that the invention may assume various alternativeorientations, except where expressly specified to the contrary. It isalso to be understood that the specific devices and processesillustrated in the attached drawings, and described in the followingspecification are simply exemplary embodiments of the inventive conceptsdefined in the appended claims. Hence, specific dimensions and otherphysical characteristics relating to the embodiments disclosed hereinare not to be considered as limiting, unless the claims expressly stateotherwise.

The present invention relates to an apparatus and method for extractingliquid from a humid mass (e.g., sludges and slurries), as those used orproduced in the pulp and paper industry, waste water treatment plants,agricultural, food and beverage industries, etc. The apparatus andmethod according to the present invention operate on the same basicextraction principle as the system and method described in U.S. Pat. No.4,534,868, the disclosure of which is hereby incorporated herein byreference. The present invention is used to remove a portion of liquidfrom the humid mass to produce a waste solid that is easy to dispose.

The reference number 10 (FIGS. 1-4) generally designates a system forextracting liquid from a mass. The illustrated system 10 for extractingliquid from a mass comprises a platform 12 having an upper surface 14, asystem mass input 16, a polymer feeding and blending system 18 on theupper surface 14, a liquid extraction assembly 40 on the upper surface14, and piping 22 having a first section 24 between the system massinput 16 and the polymer feeding and blending system 18, and a secondsection 26 between the polymer feeding and blending system 18 and theliquid extraction assembly 40. The system 10 is configured to have massinputted into the system mass input 16, transport the mass to thepolymer feeding and blending system 18 through the first section 24 ofthe piping 22, inject polymer into the mass in the polymer feeding andblending system 18, and transport the mass from the polymer feeding andblending system 18 to the liquid extraction assembly 40. Pressure frommass forced into the liquid extraction assembly 40 forces liquid in themass to exit the mass. In the illustrated embodiment, the liquidextraction assembly 40 comprises a pair of liquid extraction presses 11.However, it is contemplated that the liquid extraction assembly 40 ofthe present invention could use any number (including only one) of theliquid extraction presses 11 as described in more detail below.

In the illustrated embodiment, the system 10 can either include a sourceof mass (as shown schematically in FIG. 4) or be configured to beconnected to a source of mass (as illustrated in FIG. 1). The mass ispreferably a humid mass (e.g., sludges and slurries). As stated above,the mass can be that used or produced in the pulp and paper industry,waste water treatment plants, agricultural industries, food and beverageindustries, etc. The system 10 of the present invention removes at leasta portion of the liquid in the mass. In the illustrated embodiment, thesystem 10 is portable and can be directly brought to the pulp and paperindustry, waste water treatment plants, agricultural industry, food andbeverage industries, etc. for use at those locations. The system massinput 16 is configured to be connected to a hose that transports themass to the system 10 from the source of mass. Preferably, the system 10is located on the platform 12 that has an upper surface 14 smaller than72 square feet to provide a compact and easily movable system. However,several of the inventive features disclosed herein can be used in astationary and fixed system. In a stationary and fixed system, thesource of mass can comprise a tank 21 (see FIG. 4) having the masstherein, with the tank 21 communicating with the system mass input 16.

The illustrated system 10 preferably includes a mass feed pump 27 forassisting in drawing the mass from the source of mass through the hoseor from the tank 21. The mass feed pump 27 also provides pressure to themass to assist in moving the mass through the piping 22 and into andthrough the liquid extraction assembly 40. Mass feed pumps 27 are wellknown to those skilled in the art. After passing through the mass feedpump 27, the mass is fed into the polymer feeding and blending system18. The polymer feeding and blending system 18 is configured to beconnected to a water supply 29 for mixing water with polymer in thepolymer feeding and blending system 18. In the illustrated example, thesystem 10 includes a fitting 31 for connecting to a water supply forsupplying the polymer feeding and blending system 18 with the water. Thepolymer feeding and blending system 18 includes an injection area 28connected to the first section 24 and the second section 26 of thepiping 22 and defines a transition from the first section 24 to thesecond section 26. After the water is mixed with the polymer, acombination of the water and polymer is injected into the injection area28 for mixing with the mass from the first section 24 before the mass ismoved to the second section 26 of the piping 22. The polymer feeding andblending system 18 and the polymer used therein are well known to thoseskilled in the art. The polymer is preferably a conventional knownpolymer flocculent, such as a polyacrylamide. However, it iscontemplated that the system 10 could be used without an added polymerand without the polymer feeding and blending system 18. For example, amass such as grinding swarf could be deliquidified using the system 10without a polymer.

In the illustrated example, once the mass is moved to the second section26 of the piping 22, the mass is thoroughly mixed with the combinationof polymer and water in an adjustable mix valve 30 in the second section26 of the piping 22. The second section 26 of piping 22 preferablyincludes a first portion 32 extending vertically upwards from the mixvalve 30 to a top of the second section 26 of the piping 22. The secondsection 26 of the piping 22 also includes a second portion 34 comprisinga plurality of horizontal rows 36 of pipes, with each row 36 connectedat one end to the row 36 above and at another end at the row 36 below.The second portion 34 of the second section 26 of the piping 22 isconnected to the liquid extraction assembly 40, wherein the mass is fedinto the liquid extraction assembly 40. In the illustrated embodiment,the second section 26 of the piping 22 includes a mass bypass tube 38having a selectively opening valve for allowing the mass in the secondsection 26 of the piping 22 to bypass the liquid extraction assembly 40.It is contemplated that the mass taken out of the second section 26 ofthe piping 22 could be reinserted into the system 10 by placing the masstaken out of the second section 26 into the source of mass or directlyor indirectly into the system mass input 16. Likewise, the secondsection 26 of the piping 22 can include an extraction valve for eachliquid extraction press 11 of the liquid extraction assembly 40 forselectively allowing the mass in the second section 26 to be fed intoone or more of the liquid extraction presses 11. FIG. 4 illustrates aschematic representation of the system 10.

As shown schematically in FIG. 4, the system 10 can include at least oneconveyor 35 for accepting the solid portion of the mass exiting one ormore of the liquid extraction assemblies 40 to move the mass to adisposal or collecting device (not shown).

In the illustrated example, the liquid extraction assembly 40 acceptsthe mass from the piping 22 and outputs a solid and the at least aportion of the liquid. The liquid extraction assembly 40 of the presentinvention includes a pair of liquid extraction presses 11 connected to amotor assembly 44. In the illustrated example, the system 10 of thepresent invention comprises a pair of liquid extraction presses 11 thatshare the motor assembly 44. However, it is contemplated that only oneliquid extraction press 11 could be used or that each liquid extractionpress 11 could have its own motor assembly 44. Furthermore, the system10 can include any number of liquid extraction presses 11.

The illustrated motor assembly 44 powers the liquid extraction presses11. The motor assembly 44 includes an upright motor 51, a transferhousing 53 and a support 55. The support 55 extends upwardly from theplatform 12 between the liquid extraction presses 11. The upright motor51 includes a vertical rotary output shaft (not shown) that extends intothe transfer housing 53. The transfer housing 53 transmits the rotarymotion of the vertical rotary output shaft of the upright motor 51 to ahorizontal motor assembly output shaft 57 (see FIG. 6A) in a manner wellknown to those skilled in the art (e.g., a worm gear or any othermeans). The motor assembly output shaft 57 includes a first end 65 thatextends into a first one of the liquid extraction presses 11 and asecond end 59 that extends into a second one of the liquid extractionpresses 11. As illustrated in FIGS. 5 and 6A, the first end 65 and thesecond end 59 of the motor assembly output shaft 57 each include acylindrical portion 61 and a key flange 63 extending along alongitudinal surface of the cylindrical portion 61. The first end 65 andthe second end 59 of the motor assembly output shaft 57 power the liquidextraction presses 11 as described in more detail below.

As illustrated in FIGS. 5, 6 and 6A, each liquid extraction press 11comprises a housing 42 including an outer housing shell 46 and an innerhousing shell 48. The inner housing shell 48 (FIGS. 5, 6 and 8-11)includes a circular base wall 52, a tubular wall 54 extending from thebase wall 52 and a peripheral flange 56 extending from the tubular wall54 opposite the base wall 52. The circular base wall 52 includes a driveshaft opening 50 centrally located therein and a plurality of fasteneropenings 58 surrounding the drive shaft opening 50. The fasteneropenings 58 are configured to accept fasteners therein to connect theinner housing shell 48 to the motor assembly 44. The edge between thebase wall 52 and the tubular wall 54 includes three sanitary holes 60for allowing a cleaning fluid to be injected into the inner housingshell 48 when the liquid extraction assembly 40 is constructed to cleanthe liquid extraction assembly 40 as discussed below. Although threesanitary holes 60 are shown, any number of sanitary holes 60 could beemployed. The sanitary holes 60 can be plugged during normal use of theliquid extraction assembly 40 or opened to allow water or other cleaningfluid to be injected into the liquid extraction assembly 40 to clean theliquid extraction assembly 40. It is contemplated that the sanitaryholes 60 could have a threaded outer surface for connection to a commongarden hose. The tubular wall 54 further includes a filtrate drain 62located at a bottom of the tubular wall 54. The filtrate drain 62 allowsthe liquid extracted from the mass and any cleaning fluid injected intothe liquid extraction assembly 40 to exit the liquid extraction assembly40. The peripheral flange 56 of the inner housing shell 48 includes acircular portion 64, a bottom extending lip portion 66 and a noseportion 68. The bottom extending lip portion 66 and the nose portion 68define an open mouth 70. As explained in more detail below, the openmouth 70 is configured to have a movable side wall 72 (see FIGS. 19 and19A) inserted therein. The circular portion 64, the bottom extending lipportion 66 and the nose portion 68 all include a plurality of connectionopenings 74 for connecting a center seal 76 (described below) and theouter housing shell 46 to the inner housing shell 48. The inner housingshell 48 and the outer housing shell 46 are substantially a mirror imageof each other (except that the outer housing shell 46 does not includethe drive shaft opening 50, the mouth 70 and other details noted below).

In the illustrated example, the outer housing shell 46 includes acircular base wall 52′, a tubular wall 54′ extending from the base wall52′ and a peripheral flange 56′ extending from the tubular wall 54′opposite the base wall 52′. The circular base wall 52′ can include awindow 78 centrally located therein for viewing an interior of theliquid extraction assembly 40. The edge between the base wall 52′ andthe tubular wall 54′ includes three sanitary holes 60′ for allowing acleaning fluid to be injected into the inner housing shell 48 when theliquid extraction assembly 40 is constructed to clean the liquidextraction assembly 40 as discussed below. Although three sanitary holes60′ are shown, any number of sanitary holes 60′ could be employed. Thesanitary holes 60′ can be plugged during normal use of the liquidextraction assembly 40 or opened to allow water or other cleaning fluidto be injected into the liquid extraction assembly 40 to clean theliquid extraction assembly 40. The tubular wall 54′ further includes afiltrate drain 62′ located at a bottom of the tubular wall 54′. Thefiltrate drain 62′ allows the liquid extracted from the mass and anycleaning fluid injected into the liquid extraction assembly 40 to exitthe liquid extraction assembly 40. The peripheral flange 56′ of theinner housing shell 48′ includes a circular portion 64′ and an extensionportion 80 extending from the circular portion 64′. The extensionportion 80 has a peripheral shape substantially identical to the bottomextending lip portion 66, the nose portion 68 and the open mouth 70 ofthe inner housing shell 48. The circular portion 64′ and the extensionportion 80 include a plurality of connection openings 74′ correspondingto the connection openings 74′ of the inner housing shell 48 forconnecting the center seal 76 (described below) and the inner housingshell 48 to the outer housing shell 46.

The illustrated center seal 76 (FIGS. 5, 6, 6A, 12 and 13) is positionedbetween the inner housing shell 48 and the outer housing shell 46 anddefines an upper and lower boundary of the mass traveling through one ofthe liquid extraction presses 11 of the liquid extraction assembly 40.The center seal 76 also defines the inlet and the outlet for the sludgethrough the liquid extraction press 11. The center seal 76 includes anouter C-shaped portion 82, a scraper portion 84, a first inlet plate 86and a second inlet plate 88. The outer C-shaped portion 82 includes aninlet extension 90 and an outlet extension 92. The inlet extension 90includes a pair of grooves 94 configured to accept a top edge of thefirst inlet plate 86 and the second inlet plate 88. The outlet extension92 of the outer C-shaped portion 82 includes an angled top surface 96.The scraper portion 84 is located between the outlet extension 92 andthe inlet extension 90 of the outer C-shaped portion 82. The scraperportion 84 includes an inner annular face 98 having a scraping tip 100,a top face 102, a bottom face 104, a pair of side faces 106, and an endface 108 opposite to the inner annular face 98. A pair of upper grooves110 in the pair of side faces 106 are configured to accept a bottom edgeof the first inlet plate 86 and the second inlet plate 88. The bottomface 104 of the scraper portion 84 and the angled top surface 96 of theoutlet extension 92 of the outer C-shaped portion 82 define a top andbottom surface for the outlet of the solid portion of the sludge thattapers outwardly. It is contemplated that at least one of the side wall72 and the extension portion 80 could comprise a selectively actuatableconstriction plate as discussed below. The outer C-shaped portion 82,the scraper portion 84, the first inlet plate 86 and the second inletplate 88 each include connection openings 122 for connecting the centerseal 76 to the inner housing shell 48 and the outer housing shell 46 asdescribed below.

In the illustrated example, a rotary screen assembly 200 (FIG. 7)surrounds the center seal 76 and assists in removing the liquid portionfrom the sludge. The rotary screen assembly 200 includes a first sidedrive wheel 202, a first side slotted filter screen 204, a centerhub/spacer 206, a second side slotted filter screen 208 and a secondside drive wheel 210. The first side drive wheel 202 and the second sidedrive wheel 210 are preferably identical, but in an oppositeorientation. Likewise, the first side slotted filter screen 204 and thesecond side slotted filter screen 208 are preferably identical, but inan opposite orientation.

The illustrated first side drive wheel 202 and the second side drivewheel 210 (FIGS. 5-7) each include an outer rim 212, a plurality ofspokes 214 and an inner rim assembly 216. The outer rim 212 issubstantially circular and includes an inner periphery notch 213. Theplurality of spokes 214 each includes an inner edge 215, an outer edge217, and inside end 219 and an outside end 221. An outer rim notch 223is located at the intersection of the inner edge 215 and the outside end221. The outer rim 212 is located in the outer rim notch 223. The spokes214 also include an inner rim notch 225 located at the intersection ofthe inner edge 215 and the inside end 219. The inner rim assembly 216comprises an inner annular plate 218 and a tubular drive shaft member220. The inner annular plate 218 is located in the inner rim notch 225of the spokes 214. The inner annular plate 218 includes a base portion227 and a circular extension member 229 defining a center spacer/hubsupport notch 231 located outside of the circular extension member 229and on a surface of the base portion 227 from which the circularextension member 229 extends. The base portion 227 of the inner annularplate 218 also includes a rear notch 233 having the tubular drive shaftmember 220 therein. The inner annular plate 218 and the tubular driveshaft member 220 define a drive shaft opening 235 for accepting thefirst end 65 or the second end 59 of the motor assembly output shaft 57therein. The key flange 63 of the first end 65 or the second end 59 ofthe motor assembly output shaft 57 is accepted into a drive shaft notch237 of the drive shaft opening 235 to ensure that the tubular driveshaft member 220 and the inner annular plate 218 rotate with the motorassembly output shaft 57.

In the illustrated example, the first side slotted filter screen 204 andthe second side slotted filter screen 208 (FIGS. 5-6A, 15 and 16) eachinclude an outer rim 205, a face 207 having a plurality of slots 209 andan inner hub 230. It is contemplated that the slotted filter screenscould be made by connecting a plurality of wires to the outer rim 205and the inner hub 230, thereby defining the slots 209. Alternatively, itis contemplated that the slotted filter screens 204 and 208 could bemade by etching (for example, using water or another liquid) slots intoan annular plate, thereby forming the outer rim 205, the face 207 havingthe plurality of slots 209 and the inner hub 230. The slotted filterscreens 204 and 208 can also include a plurality of support bars 232extending between the outer rim 205 and the inner hub 230 for supportinga rear side of the face 207 having the plurality of slots 209 therein.The slots 209 allow for a high filtration area over the slotted filterscreens 204 and 208 compared to a perforated plate of the prior art,thereby providing a higher solid capture rate and easier cleaning. Thespokes 214 of the first side drive wheel 202 and the second side drivewheel 210 abut against the support bars 232 of the slotted filterscreens 204 and 208. It is contemplated that the slotted filter screens204 and 208 could have any diameter, including 24 and 36 inches. Theslots 209 preferably extend from a first point on the circumference ofthe slotted filter screens 204, 208 to a second point on thecircumference of the slotted filter screens 204, 208 (with a possibleinterruption if the slots cross the center of the slotted filter screens204, 208). As illustrated in FIG. 16, the slots 209 preferably have atriangular shape, with the larger end of the slots 209 abutting againstthe mass as the mass moves through the liquid extraction assembly 40.

The illustrated liquid extraction assembly 40 is assembled by connectingthe liquid extraction presses 11 to the motor assembly 44. In thediscussion below, only the connection of one liquid extraction press 11to the motor assembly 44 will be described. However, any remainingliquid extraction presses 11 can be connected to the motor assembly 44in a similar manner. In connecting the liquid extraction press 11 to themotor assembly 44, the first step is to connect the inner housing shell48 to the motor assembly 44 as illustrated in FIGS. 8 and 9. The innerhousing shell 48 is connected to the motor assembly 44 by first placingan annular cap 114 (see FIGS. 6 and 6A) over the second end 59 of themotor assembly output shaft 57 and connecting the annular cap 114 to thetransfer housing 53 of the motor assembly 44. The second end 59 of themotor assembly output shaft 57 is then inserted through the drive shaftopening 50 of the inner housing shell 48. The inner housing shell 48 isthen connected to the motor assembly 44 by inserting fasteners 116through the fastener openings 58 in the base wall 52 of the innerhousing shell 48 and into the annular cap 114 (which is connected to thetransfer housing 53). As illustrated in FIGS. 6 and 6A, a seal 118 islocated between the motor assembly output shaft 57 and the drive shaftopening 50 of the inner housing shell 48.

After the inner housing shell 48 has been connected to the motorassembly 44, the first side drive wheel 202 of the rotary screenassembly 200 is slid onto the second end 59 of the motor assembly outputshaft 57. The first side drive wheel 202 is slid onto the motor assemblyoutput shaft 57 by inserting the second end 59 of the motor assemblyoutput shaft 57 into the drive shaft opening 235 of the inner annularplate 218 and the tubular drive shaft member 220 of the first side drivewheel 202, with the key flange 63 of the second end 59 of the motorassembly output shaft 57 being inserted into the drive shaft notch 237of the drive shaft opening 235 as discussed above. Thereafter, thecenter hub/spacer 206 is placed around circular extension member 229 ofthe inner rim assembly 216 of the first side drive wheel 202. The firstside slotted filter screen 204 is then placed over the center hub/spacer206 by inserting the center hub/spacer 206 within an opening 120 definedby the inner hub 230 of the first side slotted filter screen 204. Oncethe first side slotted filter screen 204 is fully slid over the centerhub/spacer 206, the first side slotted filter screen 204 will abutagainst the inner edges 215 of the spokes 214 of the first side drivewheel 202 and be located between the inner periphery notch 213 of thefirst side drive wheel 202 and the center hub/spacer 206. When the firstside drive wheel 202 and the first side slotted filter screen 204 arefully connected to the motor assembly output shaft 57 as describeddirectly above, the first side drive wheel 202 and the first sideslotted filter screen 204 will be located within the inner housing shell48.

After the first side drive wheel 202, the first side slotted filterscreen 204 and the center hub/spacer 206 are assembled as describeddirectly above, the center seal 76 is positioned against the peripheralflange 56 of the inner housing shell 48 as shown in FIG. 17. The centerseal 76 is positioned such that the connection openings 122 of thecenter seal 76 are aligned with the connection openings 74 of the innerhousing shell 48. Furthermore, the outside surface of the centerhub/spacer 206 will abut the inner annular face 98 of the scraperportion 84 of the center seal 76 as illustrated in FIG. 12. Thereafter,the second side slotted filter screen 208 is slid onto the centerhub/spacer 206 by inserting the center hub/spacer 206 within an opening120 defined by the inner hub 230 of the second side slotted filterscreen 208. The second side filter screen 208 is then connected to theliquid extraction press 11 by inserting the second end 59 of the motorassembly output shaft 57 through the drive shaft opening 235 of theinner annular plate 218 and the tubular drive shaft member 220 of thesecond side drive wheel 210, with the key flange 63 of the second end 59of the motor assembly output shaft 57 being inserted into the driveshaft notch 237 of the drive shaft opening 235 as discussed above.Furthermore, the circular extension member 229 is inserted into thecenter hub/spacer 206 and the second side slotted filter screen 208 willabut against the inner edges 215 of the spokes 214 of the second sidedrive wheel 210 and be located between the inner periphery notch 213 ofthe second side drive wheel 210 and the center hub/spacer 206.Additionally, a plurality of fasteners 124 are inserted through openingsin the inner rim assemblies 216 of the first side drive wheel 202 andthe second side drive wheel 210 as illustrated in FIGS. 6 and 6A toassemble the rotary screen assembly 200. The assembly of the liquidextraction press 11 up to this point is illustrated in FIG. 18. Finally,the outer housing shell 46 is abutted against the center seal 76 and theconnection openings 74′ of the outer housing shell 46 are aligned withthe connection openings 122 in the center seal 76 and the connectionopenings 74 in the inner housing shell 48, and fasteners 126 areinserted through the connection openings 74, 74′ and 122 to connect theinner housing shell 48, the center seal 76 and the outer housing shell46. While a particular assembly procedure has been outlined above, it iscontemplated that the liquid extraction assembly 40 could be assembledin any manner. For example, the rotary screen assembly 200 can beassembled as a unitary piece before being connected to the housing 42 ofthe liquid extraction assembly 40. Furthermore, it is contemplated thatthe liquid extraction assembly 40 could include a T-shaped seal 45located between the outer housing shell 46 and the second side drivewheel 210 and between the inner housing shell 48 and the first sidedrive wheel 202 as illustrated in FIGS. 5-6A, with the T-shaped seals 45being wedged between the center seal 76, the tubular wall 54, the firstside drive wheel 202 and a stop 49 extending from the tubular wall 54 onone side and between the center seal 76, the tubular wall 54′, thesecond side drive wheel 210 and a stop 49 extending from the tubularwall 54 on the other side.

Once the liquid extraction press 11 is assembled as described above, themass will have a path through the liquid extraction press 11 defined bythe center seal 76, the first side slotted filter screen 204, the secondside slotted filter screen 208, the center spacer/hub 206, the extension80 of the outer housing shell 46 and the side wall 72. As shown in FIGS.19 and 19A, the side wall 72 is located within the open mouth 70 definedby the bottom extending lip portion 66 and the nose portion 68 of theinner housing shell 48. The side wall 72 is hinged at 134 to a rearportion 130 of the open mouth 70 (see FIGS. 1 and 9-11). The side wall72 has an air bellows 132 connected to an outer face thereof to rotatethe side wall 72 about the hinge 134. In a fully closed position asshown in FIG. 19, the side wall 72 is substantially parallel to theextension 80 of the outer housing shell 46. However, the air bellows 132can be activated to rotate the side wall 72 about the hinge 134 to widenthe exit of the liquid extraction press 11 as shown in FIG. 19A.Therefore, the mass enters into the liquid extraction press 11 through aliquid extraction assembly inlet defined by the inlet extension 90, thefirst inlet plate 86, the second inlet plate 88 and the top face 102 ofthe scraper portion 84 of the center seal 76. The mass then movestowards a rear of the center seal 76 and around the center hub/spacer206 in a path defined by the inner surface of the outer C-shaped portion82 of the center seal 76, first side slotted filter screen 204, thesecond side slotted filter screen 208 and the center spacer/hub 206.Finally, the mass exits the liquid extraction assembly through a liquidextraction assembly exit defined by the bottom face 104 of the scraperportion 84 of the center seal 76, the angled top surface 96 of theoutlet extension 92, the extension 80 of the outer housing shell 46 andthe side wall 72.

In use, the mass enters the liquid extraction assembly 40 through theinlet and is forced around the center hub/spacer 206. While the centerseal 76 and the housing 42 are fixed in position, the rotary screenassembly 200 will rotate with the motor assembly output shaft 57 asdescribed above. The pressure of the mass in the piping 22 will forcethe sludge through the liquid extraction assembly 40 towards the outletof the liquid extraction assembly. However, as the sludge is movingthrough liquid extraction assembly 40, the slotted filter screens 204,208 on either side of the mass will remove the liquid portion from thesludge as described in U.S. Pat. No. 4,534,868. As the slotted filterscreens 204, 208 remove the liquid portion from the sludge, the liquidfalls down through a pair of areas 180 (see FIG. 6A) between the rotaryscreen assembly 200 and each of the inner housing shell 48 and the outerhousing shell 46. The liquid then exits the housing 42 through thefiltrate drains 62. Furthermore, as illustrated in FIG. 2, the filtratedrains 62 can be connected to a liquid exit tube 190 adapted to beconnected to a further liquid exit element for disposing of the liquid.Therefore, the liquid portion will flow through the slotted filterscreens 204, 208 and down through the filtrate drains 62, 62′ of theouter housing shell 46 and the inner housing shell 48, respectively. Asthe mass moves in the circular path within the liquid extractionassembly 40, the scraping tip 100 of the scraping portion 84 of thecenter seal 76 will scrape the mass off of the center hub/spacer 206 andmove the mass to the outlet of the liquid extraction assembly 40. As themass moves towards the outlet of the liquid extraction assembly 40, themass will mostly (if not almost all or all) comprise the solid portionof the sludge to form the cake. Since the mass cake discharge zone istapered outward as described above, rather than straight, the sludgecake can be better controlled and bridging and/or binding of the sludgecake will be reduced.

In the illustrated example, the liquid extraction assembly 40 includesseveral features for cleaning the interior of the liquid extractionpresses 11, the first side slotted filter screen 204 and the second sideslotted filter screen 208. First, the scraper portion 84 of the centerseal 76 includes a plurality of inlet scrapers 140 (see FIG. 12)extending upward from the side faces 106 of the scraper portion 84. Theinlet scrapers 140 abut against the inside faces of the first sideslotted filter screen 204 and the second side slotted filter screen 208as the first side slotted filter screen 204 and the second side slottedfilter screen 208 rotate past the inlet scrapers 140, thereby scrapingthe inside faces of the first side slotted filter screen 204 and thesecond side slotted filter screen 208 as they rotate past the inletscrapers 140. Second, the scraper portion 84 of the center seal 76includes a plurality of cake scrapers 142 (see FIG. 12) extendingoutward from the side faces 106 of the scraper portion 84. The cakescrapers 142 abut against the inside faces of the first side slottedfilter screen 204 and the second side slotted filter screen 208 as thefirst side slotted filter screen 204 and the second side slotted filterscreen 208 rotate past the inlet scrapers 140, thereby scraping theinside faces of the first side slotted filter screen 204 and the secondside slotted filter screen 208 as they rotate past the scraper portion84 of the center seal 76. Third, the scraper portion 84 of the centerseal 76 includes a pair of wash nozzles 144 in the side faces 106 of thescraper portion 84. The scraper portion 84 includes a bore 146 throughthe scraper portion 84, with a washer fluid inlet 148 in the end face108 of the scraper portion 84 (see FIG. 13). As illustrated in FIGS. 2and 3, water entering the water supply 29 can also be directed to thewasher fluid inlet 148 in the scraper portion 84 and then into the bore146. The water is then ejected out of the bore 146 through the washnozzles 144 in the side faces 106 of the scraper portion 84, therebycleaning the first side slotted filter screen 204 and the second sideslotted filter screen 208 as they rotate past the scraper portion 84. Itis therefore contemplated that the nozzles 144 can wash and clean thefirst side slotted filter screen 204 and the second side slotted filterscreen 208 during use of the system 10 (i.e., while the mass isdeliquefied). Finally, the entire liquid extraction assembly can becleaned by injecting water or a cleaning fluid into the inner housingshell 48 and the outer housing shell 46 through the sanitary holes 60′,60, respectively, as described above.

In the illustrated embodiment, the outlet of the liquid extractionpresses 11 includes a top wall defined by the bottom face 104 of thescraper portion 84 of the center seal 76, a bottom wall defined by theangled top surface 96 of the outlet extension 92 of the center seal, afirst side wall defined by the extension 80 of the outer housing shell46 and a second side wall defined by the side wall 72. In theillustrated example, the outlet tapers outwardly because the top wall ofthe outlet is horizontal and the bottom wall tapers outwardly asdescribed above such that the mass passes from a smaller area to alarger area as the mass passes through the outlet (see FIG. 19B).Furthermore, the side walls can either be parallel or have the side wall72 taper outwardly as described above. Such an arrangement isillustrated in FIG. 19B. However, it is contemplated that the top wall,the bottom wall, the first side wall and/or the second side wall of theoutlet can taper outwardly. For example, as illustrated in FIG. 19C, thebottom face 104 of the scraper portion 84 of the center seal 76 cantaper outwardly, thereby providing the outlet with a top and bottomoutwardly tapering wall. Furthermore, it is contemplated that the bottomwall of the outlet could be horizontal and the top wall could taperoutwardly by having the bottom face 104 of the scraper portion 84 of thecenter seal 76 taper outwardly. Moreover, it is contemplated that bothside walls of the outlet can have the side wall 72 as discussed above(with the outer housing shell 46 including the open mouth 70 and asecond side wall 72 therein) such that both of the side walls of theoutlet can be selectively moved to taper outwardly. Additionally, it iscontemplated that the side wall 72 could only comprise a portion of theside wall of the outlet, with a stationary side wall 72′ being locatedunder or over the movable side wall 72 as illustrated in FIG. 19D.Furthermore, it is contemplated that both the side walls of the outletcould taper outwards in a direction from the top wall of the outlet tothe bottom wall of the outlet as shown in FIG. 19E such that thedistance between the side walls of the outlet is smaller at the top thanthe bottom of the side walls.

It is to be understood that variations and modifications can be made onthe aforementioned structure without departing from the concepts of thepresent invention, and further it is to be understood that such conceptsare intended to be covered by the following claims unless these claimsby their language expressly state otherwise.

1. A liquid extraction assembly for extracting liquid from a masscomprising: a housing having an inlet and an outlet; the housing furtherincluding a path between the inlet and the outlet; the housing beingconfigured to have the mass forced into the inlet to move the mass fromthe inlet to the outlet; the housing including two substantiallyparallel rotating screens rotating side by side and apart from oneanother, with the path extending between the screens, each screendefining one wall of the path; each rotating screen including aplurality of non-circular openings located at the path; wherein pressurefrom mass forced into the input presses the mass against thenon-circular openings of the rotating screens to thereby force at leasta portion of liquid in the mass to pass through the non-circularopenings of the rotating screens.
 2. The liquid extraction assembly ofclaim 1, wherein: the path is substantially circular.
 3. The liquidextraction assembly of claim 1, further including: a motor for rotatingthe rotating screens.
 4. The liquid extraction assembly of claim 3,further including: a shaft assembly extending from the motor to therotating screens; the shaft assembly having a right angled portion. 5.The liquid extraction assembly of claim 1, wherein: the plurality ofnon-circular openings comprises a plurality of parallel elongatednon-circular slots.
 6. The liquid extraction assembly of claim 5,wherein: each rotating screen is circular; and at least one of theelongated non-circular slots extends from a first point on thecircumference of one of the rotating screens to a second point on thecircumference of the one of the rotating screens.
 7. A method ofextracting liquid from a mass comprising: providing a housing having aninlet and an outlet, with the housing further including a path betweenthe inlet and the outlet, the housing further including twosubstantially parallel rotating screens rotating side by side and apartfrom one another, with the path extending between the screens, eachrotating screen being adjacent the path and defining one, wall of thepath, each rotating screen including a plurality of non-circularopenings therethrough, the non-circular openings being located at thepath; forcing the mass into the inlet; rotating the screen; abutting themass in the path against the non-circular openings of the screen; andforcing at least a portion of liquid in the mass through thenon-circular openings in the rotating screens.
 8. The method of claim 7,wherein: the path is substantially circular.
 9. The method of claim 7,further including: providing a motor for rotating the rotating screens;and rotating the rotating screens with the motor.
 10. The method ofclaim 9, further including: providing a shaft assembly extending fromthe motor to the rotating screens; and providing the shaft assembly witha right angled portion.
 11. A system for extracting liquid from a masscomprising: a portable platform having an upper surface; a system massinput; a liquid extraction assembly on the upper surface; and pipingbetween the system mass input and the liquid extraction assembly;wherein the system is configured to have mass inputted into the systemmass input, transport the mass to the liquid extraction assembly; andwherein pressure from mass forced into the liquid extraction assemblyforces at least a portion of liquid in the mass to exit the mass. 12.The system for extracting liquid from a mass of claim 11, wherein: theupper surface of the portable platform is less than 72 square feet. 13.The system for extracting liquid from a mass of claim 11, wherein: theliquid extraction assembly comprises at least one housing having aninlet and an outlet; the at least one housing further including a pathbetween the inlet and the outlet; the at least housing being configuredto have the mass forced into the inlet to move the mass from the inletto the outlet; the at least one housing including at least one rotatingscreen adjacent the path and defining one wall of the path; the at leastone rotating screen including a plurality of openings therethrough;wherein pressure from mass forced into the input presses the massagainst the at least one rotating screen to thereby force at least aportion of liquid in the mass to pass through the openings of the atleast one rotating screen.
 14. The system for extracting liquid from amass of claim 13, wherein: the at least one housing comprises twohousings.
 15. The system for extracting liquid from a mass of claim 14,wherein: a single motor is positioned between the housings for drivingthe rotating screens.
 16. The system for extracting liquid from a massof claim 15, further including: a shaft assembly extending from themotor to the rotating screens; the shaft assembly having a pair of rightangled portions.
 17. The system for extracting liquid from a mass ofclaim 13, wherein: the openings comprise a plurality of non-circularopenings located at the path.
 18. The system for extracting liquid froma mass of claim 17, wherein: the plurality of non-circular openingscomprises a plurality of parallel elongated non-circular slots.
 19. Theliquid extraction assembly of claim 5, wherein: the plurality ofparallel elongated non-circular slots are straight.
 20. The liquidextraction assembly of claim 1, wherein: the plurality of non-circularopenings comprises a plurality of elongated non-circular slots.
 21. Themethod of claim 7, wherein: the plurality of non-circular openingscomprises a plurality of parallel elongated non-circular slots.
 22. Themethod of claim 21, wherein: the plurality of parallel elongatednon-circular slots are straight.
 23. The method of claim 22, wherein:the plurality of non-circular openings comprises a plurality ofelongated non-circular slots.